US20120106063A1 - Displays with polarizer windows and opaque masking layers for electronic devices - Google Patents

Abstract

An electronic device may have a display. Inactive portions of the display such as peripheral portions of the display may be masked using an opaque masking layer. An opening may be provided in the opaque masking layer to allow light to pass. For example, a logo may be viewed through an opening in the opaque masking layer and a camera may receive light through an opening in the opaque masking layer. The display may include upper and lower polarizers, a color filter layer, and a thin-film transistor layer. The opaque masking layer may be formed on the upper polarizer, may be interposed between the upper polarizer and the color filter layer, or may be interposed between the color filter layer and the thin-film transistor layer. The upper polarizer may have unpolarized windows for cameras, logos, or other internal structures.

Description

BACKGROUND
• This invention relates to electronic devices and, more particularly, to display structures for electronic devices such as portable computers.
• Electronic devices such as portable computers and cellular telephones typically have displays. To provide protection from damage, many displays are provided with cover glass layers. The cover glass layer helps protect underlying display structures from scratches and other damage during use of the electronic device. A patterned layer of black ink is sometimes formed on the underside of the cover glass layer to form an opaque border region. The opaque border region can hide internal device components from view. An opening in the black ink can be provided for a camera that is mounted behind the cover glass.
• As device manufacturers strive to reduce device size and weight, it is becoming unacceptable to include potentially bulky and heavy display structures in a display. It may therefore be desirable to omit the cover glass layer from a display. Care must be taken, however, to ensure that unsightly internal components remain hidden from view and that internal components such as cameras are still able to function properly.
• It would therefore be desirable to be able to provide improved display structures in electronic devices such as portable computers and cellular telephones.
SUMMARY
• An electronic device such as a portable computer, cellular telephone, or other electronic equipment may have a display. The display may have an active portion such as a central rectangular region in which images are presented to a user of the device. Inactive portions of the display such as peripheral portions of the display may be masked using an opaque masking layer. The opaque masking layer may be formed from colored ink.
• An opening may be provided in the opaque masking layer to allow light to pass. For example, a logo or other information may be viewed through an opening in the opaque masking layer. Cameras and other internal electronic components may receive light through an opening in the opaque masking layer.
• The display may include upper and lower polarizers, a color filter layer, and a thin-film transistor layer. The opaque masking layer may be formed on the upper polarizer, may be interposed between the upper polarizer and the color filter layer, or may be interposed between the color filter layer and the thin-film transistor layer.
• The upper polarizer may have unpolarized windows. The unpolarized windows may be formed by bleaching polarizer material within the polarizer. The polarizer material may be chemically bleached or may be bleached by exposure to ultraviolet light. The camera windows may be aligned with the openings in the opaque masking layer. A camera may be aligned with an unpolarized window in the polarizer and an opening in the opaque masking layer to receive image light. A logo may be aligned with an unpolarized window in a polarizer layer and an opening in the opaque masking layer so that the logo is visible from the exterior of the device. Other internal components of the electronic device such as sensors and status indicators may also be mounted beneath unpolarized windows in the polarizer and openings in the opaque masking layer.
• Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a perspective view of an illustrative portable computer with display structures in accordance with an embodiment of the present invention.
• FIG. 2 is a perspective view of a handheld device in accordance with an embodiment of the present invention.
• FIG. 3 is a cross-sectional side view of an electronic device having a display in accordance with an embodiment of the present invention.
• FIG. 4 is a cross-sectional side view of illustrative display structures in accordance with an embodiment of the present invention.
• FIG. 5 is a cross-sectional side view of a polarizer for an electronic device display in accordance with an embodiment of the present invention.
• FIG. 6 is a cross-sectional side view of a conventional liquid crystal display (LCD) module in a portable computer.
• FIG. 7 is a cross-sectional side view of an illustrative display having a recessed polarizer layer that exposes internal device structures in accordance with an embodiment of the present invention.
• FIG. 8 is a cross-sectional side view of a polarizer layer prior to treatment to form a transparent unpolarized window in accordance with an embodiment of the present invention.
• FIG. 9 is a cross-sectional side view of the polarizer ofFIG. 8 during exposure of a portion of the polarizer to ultraviolet light to bleach the polarizer and thereby form a window in the polarizer in accordance with an embodiment of the present invention.
• FIG. 10 is a cross-sectional side view of a polarizer having a transparent unpolarized (bleached) window with which an internal device structure has been aligned in accordance with an embodiment of the present invention.
• FIG. 11 is a graph showing how transmission for a film such as a triacetate cellulose (TAC) film within a laminated polarizer may vary as a function of wavelength.
• FIG. 12 is a graph showing how absorption for a film such as a polyvinyl alcohol film in a laminated polarizer may vary as a function of wavelength.
• FIG. 13 is a cross-sectional side view of a polarizer prior to formation of a patterned masking layer on the surface of the polarizer in accordance with an embodiment of the present invention.
• FIG. 14 is a cross-sectional side view of the polarizer layer ofFIG. 14 following formation of a patterned masking layer in accordance with an embodiment of the present invention.
• FIG. 15 is a cross-sectional side view of the masked polarizer layer ofFIG. 14 showing how a liquid depolarizing agent may be applied on top of the patterned masking layer to form an unpolarized region within the polarizer layer in accordance with an embodiment of the present invention.
• FIG. 16 is a cross-sectional side view of the polarizer layer ofFIG. 15 following removal of the masking layer to complete formation of a chemically bleached unpolarized window in the polarizer layer in accordance with an embodiment of the present invention.
• FIG. 17 is a flow chart of illustrative steps involved in forming display structures including a polarizer layer with an unpolarized window and an opaque masking layer with an opening in accordance with an embodiment of the present invention.
• FIG. 18 is a cross-sectional side view of illustrative display structures having a polarizer with an unpolarized window and a patterned opaque masking layer formed on the inner surface of a color filter layer in accordance with an embodiment of the present invention.
• FIG. 19A is a cross-sectional side view of illustrative display structures having a polarizer with an unpolarized window that is aligned with a logo or other information printed on the inner surface of a color filter layer using physical vapor deposition (PVD) in accordance with an embodiment of the present invention.
• FIG. 19B is a cross-sectional side view of the display structures ofFIG. 19A following formation of an opaque masking layer over the logo in accordance with an embodiment of the present invention.
• FIG. 19C is a cross-sectional side view of the display structures ofFIG. 19B after the color filter and polarizer layers have been connected to other display structure layers such as a thin-film-transistor layer in accordance with an embodiment of the present invention.
• FIG. 20 is a cross-sectional side view of illustrative display structures having a polarizer with an unpolarized window and a patterned opaque masking layer formed on the outer surface of a color filter layer in accordance with an embodiment of the present invention.
• FIG. 21 is a cross-sectional side view of illustrative display structures having a polarizer with an unpolarized window and a patterned opaque masking layer formed within a recessed region on the outer surface of a color filter layer in accordance with an embodiment of the present invention.
• FIG. 22 is a cross-sectional side view of illustrative display structures having a polarizer with an unpolarized window and a patterned opaque masking layer that is formed on a layer of the polarizer such as a triacetate cellulose layer and that is interposed between the outer surface of the triacetate cellulose layer and an inner surface of a cover film in accordance with an embodiment of the present invention.
• FIG. 23 is a cross-sectional side view of illustrative display structures having a polarizer with an unpolarized window and a patterned opaque masking layer formed on the inner surface of a polarizer layer in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
• Electronic devices such as notebook computers, tablet computers, cellular telephones, and other computing equipment may be provided with displays.
• An illustrative electronic device such as a portable computer or other electronic equipment that has a display is shown inFIG. 1. As shown inFIG. 1,display14 ofdevice10 may be mounted inupper housing portion12A ofhousing12.Housing12 may be formed from a unibody construction in which some or all ofhousing12 is formed form a unitary piece of material (e.g., metal, plastic, or fiber composite materials) or may be formed from multiple structures that have been mounted together using adhesive, fasteners, and other attachment mechanisms. For example,housing12 may be formed from frame members and other internal supports to which external plates, housing sidewalls, bezel structures, and other structures are mounted.
• Becausehousing portion12A may be used tohouse display14,housing portion12A may sometimes be referred to as a display housing.Display housing12A may be attached tohousing portion12B (sometimes referred to as a main unit or base housing) usinghinge structures18, so thatdisplay housing12A may rotate relative tomain housing12B aroundhinge axis16.Device10 may include ports for removable media, data ports, keys such askeyboard20, input devices such astrack pad24, microphones, speakers, sensors, status indicators lights, etc.
• Display14 may have an active portion and an inactive portion.Active portion28A ofdisplay14 may have a shape such as the rectangular shape that is bounded by dashedline28D inFIG. 1. Inactive portion28I ofdisplay14 may have a rectangular ring shape or other suitable shape and may form a border around the periphery ofdisplay14. Image pixel array elements such as liquid crystal diode image pixels or other active image pixel structures may be used inportion28A to present images to a user ofdevice10. Inactive portion28I is generally devoid of image pixel elements and does not participate in forming images for a user. To hide unsightly internal components from view, internal components in inactive portion28I may be blocked from view using an opaque masking layer such as a layer of ink.
• Device10 may have components that are formed in inactive device region28I. For example,device10 may have a camera such ascamera22.Camera22 may be mounted withindisplay housing12A and may operate through a window (sometimes referred to as a camera window) indisplay14.
• Information structures26 such as a logo may be mounted ondevice10.Information structures26 may be a trademarked logo that represents a manufacturer ofdevice10, may be printed text, may be trademarked text, may be a design, may be personalized information (e.g., information identifying an owner of device10), may be formed from a combination of text and non-text information, or may include other suitable content.Information structures26 may be formed from patterned ink, patterned paint, patterned polymer, patterned metal traces, or other suitable materials.
• Information structures26 may be mounted inupper housing12A. For example,information structures26 or may be formed in inactive display region28I ofupper housing12A under a transparent window indisplay14.
• FIG. 2 is a perspective view of an illustrative configuration that may be used for a handheld electronic device.Electronic device10 ofFIG. 2 may be, for example, a cellular telephone or other handheld electronic equipment.Device10 ofFIG. 1 may havehousing12.Display14 may be mounted withinhousing12 on the front ofdevice10.Active portion28A ofdisplay14 may lie withinrectangular boundary28D. Inactive portion28I ofdisplay14 may form a boundary around the periphery ofdisplay14.Housing12 may have sidewalls that run around the periphery of device10 (as an example). The sidewall structures ofhousing12 may be formed from metal, plastic, glass, ceramic, carbon-fiber materials or other fiber-based composites, other materials, or combinations of these materials. The rear ofhousing12 may be formed from metal, plastic, a planar member such as a glass or ceramic plate, fiber-based composites, other materials, or combinations of these materials.
• Device10 may have openings such asopenings34 in the sidewalls ofhousing12.Openings34 may be used to form microphone and speaker ports, openings to accommodate button members, openings for data ports and audio jacks, etc. One or more openings may be formed in inactive region28I ofdisplay14. For example, one or more openings may be formed in inactive region28I for buttons such as button32 (e.g., a menu button). Openings such asopening30 may also be formed in inactive region28I (e.g., to form a speaker port for an ear speaker).
• Window22 may be formed over an internal structure indevice10 such as a camera (as an example). If desired, windows such aswindow22 may also be formed over information such as logo information (see, e.g.,information structures26 ofFIG. 1) to allow the logo or other information to be viewed by a user ofdevice10.
• The illustrative electronic device structures ofFIGS. 1 and 2 are merely examples. Any suitableelectronic devices10 may be provided withdisplays14.Electronic devices10 may, for example, include tablet computers, wristwatch devices, pendant devices, other miniature and wearable devices, televisions, computer displays, accessories, etc.
• A cross-sectional end view of an electronic device with a display (e.g., a device such asdevice10 ofFIG. 2, a portion ofdevice10 ofFIG. 1, etc.) is shown inFIG. 3. As shown inFIG. 3,display14 may be mounted withinhousing12 so that the exterior surface ofdisplay14 is exposed.Device housing12 may be used to enclose printed circuit boards such as printedcircuit board36. Printedcircuit board36 may be a rigid printed circuit board such as a fiberglass-filled epoxy printed circuit board (e.g., FR4), a flexible printed circuit (“flex circuit”) formed from a flexible dielectric such as a sheet of polyimide with patterned conductive traces, a rigid flex substrate, or other substrate.
• Electrical components such ascomponents37 may be mounted to boards such asboard36.Electrical components37 may include switches, resistors, inductors, capacitors, integrated circuits, connectors, cameras, sensors, speakers, or other device components. These components may be soldered or otherwise connected to board36.
• Display14 may be a touch screen display. Touch screen displays such asdisplay14 ofFIG. 3 may include an array of capacitive electrodes (e.g., transparent electrodes such as indium tin oxide electrodes), or may include a touch sensor array based on other touch technologies (e.g., resistive touch sensor structures, acoustic touch sensor structures, piezoelectric sensors and other force sensor structures, etc.) The touch structures fordisplay14 may be implemented on a dedicated touch sensor substrate such as a layer of glass or may be formed on the same layer of glass that is being used for other display functions. For example, touch sensor electrodes may be formed on a color filter array layer, a thin-film transistor layer, or other layers in a liquid crystal display (LCD).
• Display14 may, in general, be formed from any suitable type of display structures. Examples of display structures that may be used fordisplay14 include liquid crystal display (LCD) structures, organic light-emitting diode (OLED) structures, plasma cells, and electronic ink display structures. Arrangements in which display14 is formed from liquid crystal display (LCD) structures are sometimes described herein as an example. This is merely illustrative. In general,display14 may be formed using any suitable display technology.
• A cross-sectional view ofdisplay14 ofFIG. 2 is shown inFIG. 4. As shown inFIG. 4,display14 may include a backlight unit (BLU) such asbacklight unit38.Light44 forbacklight unit38 may be launched into light-guide panel51 fromlight source32.Light source32 may be formed from an array of light-emitting diodes (as an example). Reflector49 (e.g., white polyester) may be used to reflect light44 upwards (outwards) indirection46 throughdisplay module40.Optical films48 may include a diffuser layer and light collimating layers (as an example).
• Display14 anddisplay module40 may have anactive region28A that produces image pixel light43 from an array of image pixels. Image pixel light43 forms an image inactive region28A that may be viewed by a user ofdevice10. The image may include text, graphics, or other image information. A portion ofdisplay14 anddisplay module40 such as region28I may be inactive. Region28I may have a shape that surrounds the periphery ofdisplay14 anddisplay module40 as shown inFIG. 1 (as an example). Inactive region28I generally does not contain active image pixels and may include an opaque masking layer to block interior structures from view.Backlight unit38 may have a footprint that is aligned withactive region28A or may have edges that extend under some or all of inactive region28I (as shown inFIG. 4).
• Display module40 may include a lower polarizer such aslower polarizer50 and an upper polarizer such aspolarizer62. A thin layer (e.g., 3-5 microns) ofliquid crystal material58 may be interposed betweencolor filter layer60 and thin-film transistor layer52.
• Thin-film transistor layer52 may be formed on a transparent planar substrate such as a layer of glass or plastic. The upper surface of thin-film-transistor layer52 may contain pixel electrode structures and thin-film transistors (shown ascircuitry54 above dashed line56). The circuitry on thin-film-transistor layer52 may be organized into an array of image pixels that can be controlled to display images ondisplay14 for a user ofdevice10.
• Color filter layer60 may include colored filter pixel elements (e.g., red, green, and blue filter elements) that providedisplay14 with the ability to display color images.Color filter layer60 may be formed using a transparent planar substrate such as a glass or plastic substrate.
• If desired, other layers of material may be included withindisplay module40 andbacklight unit38. For example,display module40 andbacklight unit38 may include one or more layers of material for forming a touch sensor, layers of optical films such as birefringent compensating films, antireflection coatings, scratch prevention coatings, oleophobic coatings, layers of adhesive, etc.
• Polarizers such as upper (outer) polarizer62 and lower (inner)polarizer50 may be formed from multiple layers of material that are laminated together. An illustrative laminated polarizer is shown in the cross-sectional side view ofFIG. 5. As shown inFIG. 5, polarizer62 (i.e., an upper polarizer in this example) may havepolarizer film68.Film68 may be formed from a stretched polymer such as stretched polyvinyl alcohol (PVA) and may therefore sometimes be referred to as a PVA layer. Iodine may be placed on to the stretched PVA film so that iodine molecules align with the stretched film and form the polarizer. Other polarizer films may be used if desired.Polarizer film68 may be sandwiched betweenlayers66 and70.Layers66 and70 may be formed from a material such as tri-acetyl cellulose (TAC) and may sometimes be referred to as TAC films. The TAC films may help hold the PVA film in its stretched configuration and may protect the PVA film. Other films may be laminated to film68 if desired.
• Coating layer72 may be formed from one or more films of material that providepolarizer62 with desired surface properties. For example,layer72 may be formed from materials that providepolarizer62 with antiglare (light diffusing) properties, antireflection properties, scratch resistance, fingerprint resistance, and other desired properties.Layer72 may be formed from one or more layers of material such as antireflection (AR) layers (e.g., films formed from a stack of alternating high-index-of-refraction and low-index-of-refraction layers), antiglare (AG) layers, antireflection-antiglare (AR/AG) layers, oleophobic layers, antiscratch coatings, or other coating layers. The functions of these layers need not be mutually exclusive. For example, an antiglare film incoating72 may help provide polarizer62 with scratch resistance.
• Polarizer62 may, if desired, be provided with a layer of adhesive such as adhesive64 (e.g., optically clear adhesive) to help attachpolarizer62 to the upper surface of display module40 (i.e.,color filter60 ofFIG. 4). The thickness ofpolarizer62 may be about 50-200 microns (as an example).
• It is often desirable to mount cameras within the interior of an electronic device. Conventionally, a camera may be mounted under a layer of cover glass in the inactive portion of a display. This type of arrangement is shown inFIG. 6. As shown inFIG. 6,conventional device structures74 may includecover glass76.Cover glass76 may be associated with a display that has active and inactive regions. For example,cover glass76 ofFIG. 6 may be associated withinactive display region98 andactive display region100.
• Black ink layer78 is formed on the underside ofcover glass76 ininactive region98 and blocks internal components such ascamera86 from view.Black ink layer78 hasopening80 forcamera86. During operation, light82 from an image can pass throughlayer76 andopening80 intolens84 ofcamera86.Display module96 is mounted underactive region100.Display module96 includescolor filter layer92, thin-film transistor layer94,upper polarizer90, and other LCD layers mounted withinchassis structure88.Black ink78hides chassis structure88 from view.
• The illustrative structures ofdisplay14 ofFIG. 4 do not include a cover glass layer. In this type of arrangement, it may be desirable to mount cameras and other internal structures under a portion of a housing that is separate from display14 (e.g., under a camera opening in a bezel or other housing structure). If desired, a camera or other internal device structure may be mounted under a portion of the display module. As shown inFIG. 7, for example,internal structure102 may be mounted below an edge portion of color filter layer60 (as an example).Internal structure102 may be a camera (e.g., a camera that receives image light throughlayer60, a sensor that receives light throughlayer60, patterned information structures in the shape of a logo or other information such asstructures26 ofFIG. 1, a status indicator (e.g. a status indicator element that emits light through layer60), or other suitable internal structures indevice10.
• Polarizer62 may interfere with the operation ofinternal structure102. For example, ifinternal structure102 is a camera, the presence ofpolarizer62 above the camera's image sensor may reduce light intensity and may therefore adversely affect camera performance. As another example, ifinternal structure102 includes patterned structures that form a logo or other information, the presence ofpolarizer62 may make it difficult to viewinternal structures102 from the exterior ofdevice10. The operation of light sensors, status indicators, and other electronic components may also be adversely affected by the presence ofpolarizer layer62.
• One way to minimize any possible adverse impact frompolarizer layer62 involves removing portions ofpolarizer layer62, so thatcolor filter layer60 is exposed. Portions ofpolarizer layer62 may be removed following attachment oflayer62 to layer60 or portions ofpolarizer layer62 may be removed prior to attachinglayer62 to layer60. The portions oflayer62 that are removed may have circular shapes (e.g., for forming a circular opening that is aligned with a camera lens), rectangular shapes (e.g., for exposing a logo or other information that has a rectangular outline), or other suitable shapes. As shown in the example ofFIG. 7,polarizer62 may be removed inregion104 along the edge portion ofcolor filter60, to avoid overlap betweenpolarizer62 and internal structures.
• Arrangements of the type shown inFIG. 7 may give rise to a step in height at the end of polarizer62 (i.e., at the interface betweenpolarizer62 and region104). In some circumstances, this step may be visible or may allowpolarizer62 to peel away fromcolor filter60.
• To avoid creating a step in height, the optical properties in polarizer may be modified to create step-less unpolarized windows that are integral parts ofpolarizer62. For example, a portion ofpolarizer62 may be exposed to light with an intensity and wavelength suitable for bleaching (depolarizing) the polarizer material withinpolarizer layer62. Following light exposure, unexposed portions ofpolarizer62 will function as polarizer layers. The exposed portions ofpolarizer62 will not have significant polarizing properties and will serve as transparent windows. Unpolarized windows may also be formed inpolarizer62 using other localized treatments (e.g., exposure to a liquid that chemically bleachespolarizer62, etc.). Using this type of arrangement,polarizer62 and its unpolarized window regions can smoothly overlap inactive display regions28I (see, e.g.,FIG. 1) without introducing steps in height.
• An illustrative process for bleachingpolarizer62 by applying light to a localized region ofpolarizer62 is shown inFIGS. 8,9 and10. Initially,polarizer layer62 is formed from a layer of polarizer material with no bleached regions (FIG. 8). As shown inFIG. 9,light source106 may emit light108 (e.g., ultraviolet light) that strikes a localized region of the surface ofpolarizer62.Light108 may be localized using a focusing arrangement (e.g., using a lens), using a mask (e.g., using a shadow mask or a patterned masking layer formed on the surface of polarizer62), using other suitable masking techniques, or using a combination of these techniques. The localization oflight108 withinpolarizer62 causesportion110 ofpolarizer62 to lose its polarizing properties and form a clear window such aswindow112.
• As shown inFIG. 10,polarizer layer62 may be mounted in a device so thatinternal structure102 is aligned withwindow112. The material in window110 (e.g.,portion110 of polarizer62) is not polarized, sowindow112 may allow light to pass freely between the exterior surface ofpolarizer layer62 andinternal structure102.
• The intensity and wavelength oflight108 may be selected so as to effectivelybleach polarizer62 without inducing optical damage to polarizer62 that could adversely affect the transparency and optical clarity ofwindow112. If, for example,polarizer62 is formed from a stretched PVA layer with a coating of aligned iodine molecules such aslayer68 ofFIG. 5, light108 is preferably able to break iodine bonds or otherwise disorder the PVA polarizer layer without damaging adjacent layers such as TAC layers66 and70. As shown inFIG. 11, TAC layers66 and70 may exhibit satisfactory transmission at wavelengths above about 380 nm or 400 nm.FIG. 12 shows how PVA absorption (i.e., the absorption inlayer68 ofFIG. 5) may decrease as a function of increasing wavelength.
• Taking into consideration the properties ofTAC films66 and70 (perFIG. 11) and the properties of PVA film (perFIG. 12), satisfactory disruption of the polarizer inlayer68 without excessive absorption and resulting damage in TAC layers66 and68 may be achieved by operatingsource106 ofFIG. 9 with wavelengths in the range of 380-420 or other wavelengths. Longer wavelengths will be less efficient atbleaching polarizer62, as indicated by the graph ofFIG. 12, but longer wavelengths will also be less likely to be absorbed in TAC layers66 and70 and will therefore tend to be less likely to adversely affect the transparency of TAC layers66 and70. Ultraviolet light (light with a wavelength of less than 420 nm or less than 400 nm in wavelength) is typically satisfactory for light-bleaching polarizer layer68, but other types of light may be used if desired.
• The intensity oflight108 may be adjusted based on its wavelength. For example, in a scenario in which light108 has wavelengths in the range of 380-420 nm (as an example), a dose of about 10 J/cm²to 100 J/cm²(or more or less than 10 J/cm²or 100 J/cm²) may be applied tolayer62 to createwindow112.
• Unpolarized window112 inpolarizer layer62 may also be formed by chemical treatment. Consider, as an example, the application of bleaching liquid topolarizer layer62, as illustrated inFIGS. 13-16. As shown inFIG. 13,polarizer layer62 may initially contain no window regions. A masking layer such asmasking layer114 ofFIG. 14 may be applied to the surface ofpolarizer layer62. Maskinglayer114 may contain one or more openings such asopening116. Maskinglayer114 may be pattered using photolithographic techniques (e.g. when maskinglayer114 is formed from a photosensitive material such as photoresist), may be patterned by pad printing, spraying, inkjet printing, etc. Opening116 may have a size and shape suitable for forming an unpolarized window withinpolarizer62. As shown inFIG. 15, afterlayer114 has been formed, a bleaching agent such asliquid118 may be deposited on the surface oflayer62 inopening116.Liquid118 may be, for example, a base such as NaOH, KOH, or other substance that removes the polarization from exposed portions ofpolarizer layer62. As shown inFIG. 16, following application and removal ofmasking layer114 and liquid118 (or other suitable bleaching agent),polarizer62 may remain polarized in all areas exceptunpolarized window112.
• During assembly ofpolarizer62 intodevice10,window112 may be aligned with a camera, information structures such as a logo, or other internal components indevice10, as described in connection withwindow112 ofFIG. 10. To ensure that potentially unsightly internal portions ofdevice10 are blocked from view,device10 may be provided with one more opaque masks. For example, one or more opaque masking layers may be incorporated onto one or more of the layers of material indisplay module40 ofFIG. 4. The opaque masking layer may be formed from black ink, ink with other (non-black) colors (e.g., white, silver, gray, red, blue), an opaque polymer, a layer of metal, or other suitable opaque substances. Examples of locations in which the opaque masking layer may be formed inmodule40 include position P1 on the top ofpolarizer62, position P2 on the lower surface ofpolarizer62, position P3 on the top surface ofcolor filter layer60, and position P4 on the lower surface ofcolor filter layer60. Other masking layer locations and combinations of masking layer locations may be used if desired.
• Illustrative steps involved in forming windows inpolarizer layer62 and in forming opaque masking layers and display module structures within an electronic device are shown inFIG. 17.
• Atstep120, layers of material such asTAC films66 and70 andpolarizer layer68 may be laminated together to formpolarizer62. For example, an extrusion tool may be used to stretchPVA layer68 and laminating rollers may be used tolaminating layers66 and70 tolayer68. Iodine may be incorporated into the polarizer (e.g., on layer68).
• If desired,window112 may be formed in the laminated polarizer layers during the operations of step122 (i.e., prior to dividing the TAC and PVA sheets into device-sized panels with a die press or other cutting tool at step124). Following cutting to form individual panels of polarizer, the polarizer may be laminated to color filter layer60 (step126).
• Alternatively, the layers of polarizer that have been laminated together during the operations ofstep120 may be divided into individual panels during the operations of step130 (i.e., before formingwindow112 inpolarizer62 during the operations of step132). With this type of approach, the panel of polarizer in whichwindow112 is formed duringstep132 may be laminated tocolor filter layer60 atstep126.
• If desired, polarizer that has been cut into device-sized panels during the operations ofstep130 may be laminated to color filter layer60 (step134) before forming window112 (step136).
• Regardless of the order in which polarizer62 is processed to formwindow112 and attached tocolor filter layer60,polarizer62 and other display structures may, during the operation ofstep128 be assembled intodevice10 so that a camera or other internal structures (see, e.g.,structure102 ofFIG. 10) are mounted in alignment withwindow112. Prior to the assembly operations ofstep128 or during assembly, opaque masking layers may be formed on the layers of material that formdisplay14. For example, a patterned layer of ink or other opaque masking material may be formed in locations such as locations P1, P2, P3, and P4 in display module40 (see, e.g.,FIG. 4). Patterned masking layers may be formed using physical vapor deposition, pad printing, screen printing, spraying, dipping, inkjet printing, shadow mask deposition, photolithographic patterning, or other suitable deposition and patterning techniques. Examples of materials that may be used as opaque masking layers include metals, polymers, ink, paint, tinted adhesive, oxides (e.g., metal oxides), fiber-based composites, etc.
• FIG. 18 is a cross-sectional side view of display structures in which an opaque masking layer has been formed in a position such as position P4 ofFIG. 4 undercolor filter layer60. As shown inFIG. 18,display module40 may haveactive region28A and inactive region28I.Opaque masking layer138 may be formed on the inner surface ofcolor filter layer60.Opaque masking layer138 may be patterned to form an opening such asopening140. Opening140 may have a size and shape that allows some or all ofopening140 to overlapwindow112 inpolarizer layer62. This allows light to pass betweeninterior structure102 and the exterior ofmodule40 adjacent to polarizer62 viawindow112,color filter60, opening140, and thin-film transistor layer52 (as an example). During deposition operations, some or all ofmasking layer138 may overlap existing structures on color filter60 (e.g., structures such asstructure142 ofFIG. 18 that are formed of chromium or other materials and that are used in forming light-blocking patterns for the color filter elements in filter60). If desired, some ofstructures142 may be used in forming layers such aslayer138.
• As shown inFIG. 18,internal structures102 may be aligned along commonvertical axis114 withwindow112 andmask opening140.Structures102 may include a camera (image sensor), a status indicator, information structures such as a logo or other printed or patterned information, a sensor, etc.
• FIGS. 19A,19B, and19C show howinternal structures102 such as information structures that form a logo or other information may be formed on the lower surface ofcolor filter layer60 in a configuration in whichmasking layer138 is being formed in a position such as position P4 ofFIG. 4. As shown inFIG. 19A,structures102 may be formed on the lower surface ofcolor filter60.Structures102 may, for example, be formed underwindow112 in polarizer layer62 (i.e., so that the outline ofstructures102 is contained within the outline ofwindow112 and so thatwindow112 completely overlaps structures102).Structures102 may be formed from ink, metal, paint, polymer, or other materials and may be deposited using physical vapor deposition (PVD) or other suitable deposition and patterning techniques.
• Following deposition ofstructures102 on the inner surface ofcolor filter layer60,opaque masking layer138 may be formed overstructures102, as shown inFIG. 19B. In particular, a layer of black ink or other opaque masking substance may be formed over structures102 (e.g., a PVD logo) using screen printing, inkjet printing, pad printing, or other suitable deposition techniques.Opaque masking layer138 may cover the inactive portion of display14 (see, e.g., inactive portion28I ofFIG. 1).
• As shown inFIG. 19C, following formation of structures102 (e.g., a PVD logo or other information) and formation of patternedmasking layer138,display module40 may be completed by attachinglower polarizer50 and thin-film-transistor layer52 belowliquid crystal material58,color filter layer60, andupper polarizer62.
• FIG. 20 is a cross-sectional side view ofdisplay module40 in a configuration in whichopaque masking layer138 has been formed in a position such as position P3 ofFIG. 4 (i.e., on top of color filter layer60). As shown inFIG. 20,polarizer62 may be provided withunpolarized window112 that is aligned with internal structures102 (e.g., a logo or other information, a camera, a sensor or other electrical component, etc.).Opaque masking layer138 may have an opening such asopening140 that is aligned withwindow112 andstructures102.Polarizer layer62 may be attached to displaymodule40 using adhesive148 (e.g., a layer of adhesive that is about 0.5 to 6 microns thick).Opaque masking layer138 may be about 40 to 120 microns thick (as an example). If desired,planarizing layer146 may be interposed betweenpolarizer62 and the upper surface ofcolor filter layer60 to help accommodate the thickness ofopaque masking layer138.Planarizing layer146 may be formed from epoxy or other adhesive (e.g., some of adhesive148), spin-on-glass, polymer, or other clear material.Opaque masking layer138 may be formed from white ink, black ink, non-black colored ink, or other suitable opaque materials.
• As shown in the cross-sectional side view ofFIG. 21,color filter layer60 may, if desired, be provided with a recess such asrecess150. Recess150 may have a depth (thickness) comparable to the thickness of opaque masking layer138 (e.g., about 40-120 microns as an example). In this type of configuration, opaque masking layer (and, if desired, optional filler material152) may be recessed withinrecess150 so that the outermost surface of opaque masking layer138 (and optional filler material152) is flush or nearly flush with the outermost surface of color filter layer160.Filler material152 may be formed from adhesive (e.g., some of adhesive148), polymer, or other suitable transparent materials.
• A cross-sectional side view of an illustrative configuration that may be used fordisplay module40 in whichopaque masking layer138 is formed on polarizer62 (e.g., in position P1 ofFIG. 4) is shown inFIG. 22. As shown inFIG. 22,polarizer62 may include a polarizer layer such asPVA layer68 and TAC layers such as TAC layers66 and70 or other optical films.Polarizer62 may be attached to color filter layer60 (e.g., using adhesive).Opaque masking layer138 may be formed on the surface ofTAC layer70. Opening140 may be aligned withwindow112 inpolarizer62.Cover film72 may be attached to the outer surface of TAC layer70 (e.g., to form the outermost surface of display module40).Cover film72 may be a cover layer that includes one or more layers such as antireflection layers, antiglare layers, antiscratch layers, etc.Cover film72 may be dispensed from one or more rolls of film and may be attached toTAC layer70 usingadhesive154. In this type of arrangement,opaque masking layer138 may be aligned with the panel of material that formspolarizer62 to a relatively high tolerance (e.g., to a 0.1-0.4 mm tolerance), becauselayer138 can be aligned directly to the polarizer panel during printing operations or other opaque masking layer deposition operations (as an example). If desired,opaque masking layer138 may be deposited onto the underside ofcover film72 beforecover film72 is attached topolarizer62.
• FIG. 23 is a cross-sectional side view of illustrative structures fordisplay module40 showing howopaque masking layer138 may be formed on the underside ofpolarizer62 in alignment withwindow112.Adhesive64 may be used to attachpolarizer62 tocolor filter layer60 whenpolarizer62 is moved indirection156. A recess may be provided incolor filter layer60 to help accommodate the thickness ofopaque masking layer138, a layer of planarizing material may be interposed betweenpolarizer62 andcolor filter60, or other actions may be taken to help ensure thatpolarizer62 is satisfactorily attached tocolor filter60.
• The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.

Claims (34)

1. An electronic device, comprising:

a display having an active region and an inactive region;

a polarizer in the display, wherein the polarizer overlaps the active region and the inactive region; and

an unpolarized window in the polarizer within the inactive region, wherein the unpolarized window contains material from the polarizer.

2. The electronic device defined inclaim 1 wherein the polarizer comprises a layer of polarizing material and wherein the unpolarized window comprises a bleached portion of the layer of polarizing material.

3. The electronic device defined inclaim 1 wherein the polarizer comprises a layer of polarizing material and wherein the unpolarized window comprises an ultraviolet-light-bleached portion of the layer of polarizing material.

4. The electronic device defined inclaim 3 wherein the polarizer comprises iodine and wherein the layer of polarizing material comprises a layer of polyvinyl alcohol.

5. The electronic device defined inclaim 1 wherein the polarizer comprises a layer of polarizing material and wherein the unpolarized window comprises a chemically bleached portion of the layer of polarizing material.

6. The electronic device defined inclaim 5 wherein the polarizer comprises iodine and wherein the layer of polarizing material comprises a layer of polyvinyl alcohol.

7. The electronic device defined inclaim 1 further comprising an electronic component mounted in alignment with the unpolarized window.

8. The electronic device defined inclaim 1 further comprising a camera that receives light through the unpolarized window.

9. The electronic device defined inclaim 8 further comprising a logo that receives light through the unpolarized window.

10. The electronic device defined inclaim 9 wherein the display comprises a color filter layer and wherein the logo comprises material on the color filter layer.

11. The electronic device defined inclaim 10 further comprising an opaque masking layer that covers the logo.

12. The electronic device defined inclaim 11 further comprising a thin-film transistor layer in the display, wherein the opaque masking layer and the logo are interposed between the color filter layer and the thin-film transistor layer.

13. Apparatus, comprising:

a color filter layer;

a thin-film transistor layer; and

an opaque ink layer that is interposed between the color filter layer and the thin-film transistor layer.

14. The apparatus defined inclaim 13 further comprising:

first and second polarizers, wherein the color filter layer and the thin-film transistor layer are interposed between the first polarizer and the second polarizer, wherein the color filter layer has an outer surface and an inner surface and wherein at least some of the ink layer is formed on the inner surface.

15. The apparatus defined inclaim 14 wherein the first polarizer comprises an unpolarized window and wherein the opaque ink layer has an opening that is aligned with the unpolarized window.

16. The apparatus defined inclaim 15 further comprising a camera that receives light through the unpolarized window and the opening.

17. The apparatus defined inclaim 14 wherein the first polarizer comprises an unpolarized window and wherein the apparatus further comprises a logo that is visible through the unpolarized window.

18. Apparatus, comprising:

a color filter layer;

a thin-film transistor layer;

first and second polarizers, wherein the color filter layer and the thin-film transistor layer are interposed between the first polarizer and the second polarizer and wherein the color filter layer is interposed between the first polarizer and the thin-film transistor layer; and

an opaque masking layer that is interposed between the first polarizer and the color filter layer.

19. The apparatus defined inclaim 18 wherein the color filter layer comprises portions defining a recess and wherein the opaque masking layer is formed on the color filter layer in the recess.

20. The apparatus defined inclaim 18 wherein the opaque masking layer comprises ink.

21. The apparatus defined inclaim 18 wherein the first polarizer comprises an unpolarized window and wherein the opaque masking layer has an opening that is aligned with the unpolarized window.

22. The apparatus defined inclaim 21 further comprising a camera that receives light through the unpolarized window and the opening.

23. The apparatus defined inclaim 18 wherein the first polarizer comprises an unpolarized window and wherein the apparatus further comprises a logo that is visible through the unpolarized window.

24. Apparatus, comprising:

a color filter layer;

a thin-film transistor layer;

first and second polarizers, wherein the color filter layer and the thin-film transistor layer are interposed between the first polarizer and the second polarizer and wherein the color filter layer is interposed between the first polarizer and the thin-film transistor layer; and

an opaque masking layer on the first polarizer.

25. The apparatus defined inclaim 24 further comprising a cover film, wherein the opaque masking layer is interposed between the cover film and the first polarizer.

26. The apparatus defined inclaim 24 wherein the polarizer comprises first and second triacetate cellulose layers and a polyvinyl alcohol film interposed between the first and second triacetate cellulose layers and wherein the opaque masking layer is formed on the first triacetate cellulose layer.

27. The apparatus defined inclaim 26 wherein the cover film comprises an antireflection coating.

28. The apparatus defined inclaim 26 wherein the cover film comprises an antiglare coating.

29. The apparatus defined inclaim 24 wherein the first polarizer comprises an unpolarized window and wherein the opaque masking layer has an opening that is aligned with the unpolarized window.

30. The apparatus defined inclaim 29 further comprising a camera that receives light through the unpolarized window and the opening.

31. The apparatus defined inclaim 24 wherein the first polarizer comprises an unpolarized window and wherein the apparatus further comprises a logo that is visible through the unpolarized window.

32. The apparatus defined inclaim 24 wherein the opaque masking layer comprises ink.

33. A computer, comprising:

a display having a polarizer layer, a color filter layer, and a thin-film transistor layer; and

a housing in which the display is mounted, wherein the polarizer layer comprises at least one unpolarized window.

34. The computer defined inclaim 33 further comprising:

a camera; and

a logo, wherein the at least one polarized window comprises first and second unpolarized windows in the polarizer layer, wherein the camera receives light through the first unpolarized window, and wherein the logo is visible through the second unpolarized window.

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